textproduct: Rapid City

KEY MESSAGES

- Dry and above average temperatures through Wednesday with elevated to near-critical fire weather conditions; warmest and driest Wednesday ahead of a cold front.

- Cold front to bring more seasonable temperatures Thursday along with spotty light showers, although most areas will remain dry.

- Trending mild and dry again Friday into next weekend with elevated fire weather conditions likely.

UPDATE

Issued at 956 PM MDT Mon Mar 23 2026

Surface analysis shows temperatures dropping this evening into the 40s, especially behind a weak cool front which is approaching the Black Hills and is progged to stall near I-90 tonight. Low amplitude ridging aloft centered over the Pac NW will continue eastward over the next couple of days, with the main axis reaching the northern High Plains by Wednesday. Warm air advection will redevelop across NE WY/SW SD Tuesday morning. Forecast looks on track with warming temps both Tuesday and Wednesday before the next cold front cools things back closer to near climatology (still slightly warmer, actually). Main focus of the forecast are the fire weather concerns, which will be addressed below.

DISCUSSION

(This Evening Through Monday) Issued at 1238 PM MDT Mon Mar 23 2026

Largely zonal flow as upper ridging builds over the western half of the country. Surface high pressure has settled into the upper/middle Mississippi Valley. West-southwestern mid-level flow is advecting warmer air into the region, although lingering low clouds across south-central SD are slowing heating this afternoon.

Upper level high over the southwest US will dominate the weather through at least mid-week as upper ridging persists. Warmest day Wednesday with widespread 70s and lower to mid 80s (mainly along and south of I-90). Elevated fire weather conditions this afternoon and again Tuesday, although critical conditions are not expected. Critical conditions are possible Wednesday, especially across northeastern Wyoming into the Black Hills and southwestern South Dakota, where a Fire Weather Watch is now in effect. Lower confidence in winds reaching critical thresholds across western South Dakota. Some forecast soundings show slightly lower mixing heights, however, if we are able to mix above 700-600mb into the higher momentum air aloft, gusts > 25 mph will be more likely.

A cold front will surge through the forecast area late Wednesday evening through Thursday morning, shifting winds northwest and increasing behind the front. Spotty light showers are possible behind the front across northwestern South Dakota, but precipitation amounts will be limited. Slightly above seasonable temperatures Thursday and Friday before warmth returns along with elevated to near-critical fire weather conditions into the weekend.

AVIATION

(For the 12Z TAFS Through 12Z Wednesday Morning) Issued At 600 AM MDT Tue Mar 24 2026

VFR conditions are expected through the forecast period.

FIRE WEATHER

Issued At 956 PM MDT Mon Mar 23 2026

Elevated fire weather conditions will continue Tuesday afternoon across portions northeast WY through far SW SD. Conditions fall short of nearing critical thresholds; however, with min RH reaching 18-25%, monitoring is still prudent. Winds will remain relatively light through Tuesday afternoon, with occasional gusts to 10-20mph.

The main concern continues to be Wednesday across northeastern Wyoming, the Black Hills (particularly central and southern BHs), and southwestern South Dakota where relative humidity at or below 15% will be possible. Highs will warm into the 70s to mid 80s with gusty west winds across these areas (gusts 25 to 40 mph) with lighter winds on the western SD plains. There is potential for greater mixing on the plains, which would result in a better chance of critical winds; will continue to monitor for that potential.Fire Weather Watch continues with no changes.

A cold front Wednesday evening will bring cooler temps Thursday, min RH of 30-40%, and NW winds gusting to 30-40 mph. Outside of spotty light showers, the frontal passage is expected to be dry.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Fire Weather Watch from Wednesday morning through Wednesday evening for SDZ319>326-332-333. WY...Fire Weather Watch from Wednesday morning through Wednesday evening for WYZ314>318.